Database for Polyphenol Utilized Proteins from gut microbiota



Translocase is a general term for a protein that assists in moving another molecule, usually across a cell membrane. These enzymes catalyze the movement of ions or molecules across membranes or their separation within membranes. The reaction is designated as a transfer from “side 1” to “side 2” because the designations “in” and “out”, which had previously been used, can be ambiguous1. Translocases are the most common secretion system in Gram positive bacteria.

The enzyme classification and nomenclature list was first approved by the International Union of Biochemistry in 1961. Six enzyme classes have been recognized based on the type of chemical reaction catalyzed, including oxidoreductases (EC 1), transferases (EC 2), hydrolases (EC 3), lyases (EC 4), isomerases (EC 5) and ligases (EC 6). However, it was not noticed back at the time that none of these classes clearly describe an important group of enzymes, which move ions or molecules across membranes or their separation within membranes. Although the hydrolytic reaction is not the primary function, several of these enzymes are involved the hydrolysis of ATP had been previously classified as ATPases (EC 3.6.3.-). Nowadays, these enzymes have been classified under a new EC class of translocases (EC 7).

Translocase are sorted as EC 7 in the EC number classification of enzymes and can be further classified into seven subclasses.


The reaction most translocases catalyse is:

AX + Bside 1|| = A + X + ||Bside 2 2

A clear example of an enzyme that follows this scheme is H+-transporting two-sector ATPase:

ATP + H2O + 4H+side 1 = ADP + phosphate + 4H+side 2

This ATPase carries out the dephosphorylation of ATP into ADP while it transports H+ to the other side of the membrane3. However, other enzymes that also fall into this category do not follow the same reaction scheme. This is the case of ascorbate ferrireductase:

ascorbateside 1 + Fe(III)side 2 = monodehydroascorbateside 1 + Fe(II)side 2

In which the enzyme only transports an electron in the catalysation of an oxidoreductase reaction between a molecule and an inorganic cation located on different sides of the membrane4.

For a detailed information on class, subclass or sub-subclass of oxidoreductases, please visit ExplorEnz.

Pfam Information

No pfam information.

TRs Subfamily Number

No subfamilies are found.

EC in TRs Families (sorted by counts)

No EC activities.


  1. “EC class 7”. ExplorEnz - The Enzyme Database. Retrieved 24 October 2019. 

  2. Tipton K, McDonald A. A Brief Guide to Enzyme Nomenclature and Classification[J]. 2018. 

  3. “ExplorEnz: EC”. Retrieved 2019-10-24. 

  4. “BRENDA - Information on EC - ascorbate ferrireductase (transmembrane)”. Retrieved 2019-10-24. 

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